High molecular weight polyalkyleneamines have found use in many applications. For example, they have been used to make ashless oil dispersants for lubricating oil additives, and as asphalt additives. High molecular weight polyalkyleneamines have also been derivatized to make polyamides, which in turn are useful as epoxy curing agents.
The most widely practiced commercial process for the production of high molecular weight polyalkyleneamines is based on the reaction of ethylene dichloride (EDC) with ammonia (NH3) followed by neutralization with sodium hydroxide (NaOH) to produce polyethyleneamines and salt. This process is sometimes referred to as the “EDC Process”.
Another family of high molecular weight polyalkyleneamines includes polyethyleneimines (PEI), which are produced by an acid-catalyzed ring opening homopolymerization of ethyleneimine (or aziridine). These materials can range in molecular weight from 800-750,000 and comprise a combination of primary, secondary, and tertiary amino groups, typically in a molar ratio of approximately 1:2:1 with a branching site every 3-3.5 nitrogen atoms along any given chain segment. Depending on the reaction conditions different degrees of branching can be achieved.
Other publications that disclose the preparation of high molecular weight polyalkyleneamines include U.S. Patent Publication 2009/0018040, which discloses a method in which lower molecular weight ethyleneamines are coupled through the use of difunctional linking groups such as epihalohydrins, maleates, α-halogenated acids, and malonates.
Another method for making polyalkyleneamines involves the transamination of lower molecular weight polyalkyleneamines. See for example, GB Patent No. 1508460 and U.S. Pat. Nos. 4,568,746 and 7,053,247, which each discloses the transamination of ethylenediamine (EDA). See also GB Patent No. 1551127 which discloses the transamination of 1,3-diaminopropane (1,3-DAP); U.S. Pat. No. 6,465,601 which discloses the preparation of mixed amines by the transamination of a substituted phenolic compound (Mannich base) with another amine; US 2008/0132725 A1 which discloses the preparation of bis(3-aminopropyl)amine [dipropylenetriamine (DPTA)] by the continuous reaction of 1,3-propylenediamine in the presence of a heterogeneous catalyst in a reaction column; WO 2010042159 which discloses the manufacture of cyclic triamines by the transamination of tris(2-aminoethyl)amine (TAEA) to produce 2-(piperazin-1-yl)ethanamine (AEP); and United States Published Patent Application 2013-0225864 A1 which discloses the manufacture of high molecular weight predominantly linear acyclic, non-branched amines.
These methods tend to produce product mixtures whose contents promote either the formation of cyclic polyalkyleneamines or linear non-branched polyalkyleneamines and discourage the formation of higher molecular weight, branched, acyclic polyalkyleneamines. As a result there remains a need for a method to better control the product mix for making high molecular weight, branched acyclic, polyalkyleneamines.
While cyclic and linear non-branched species are desired for some applications, higher molecular weight, branched, acyclic species are also desired for many other applications. For example, they are useful in paper manufacture, water treatment conditioning, as plating bath agents, as dispersing agents, as asphalt additives, as corrosion inhibitors, as epoxy curing agents, as fuel and lubricant additives, as mineral processing aids, in wood treating, etc. Other exemplary uses for product mixtures of the invention include other polymer curing, hydrocarbon purification, surface activation, in fabric softeners, as textile additives, and as surfactants.
Applicants have discovered an efficient and effective methodology for producing high molecular weight, branched acyclic polyalkyleneamines that are substantially free of cyclic amine species.